1. Field of the Invention
This invention relates to communications. Specifically, the setup of a communication call.
2. Description of the Prior Art
Conventional communications networks often include packet-switched technology. Although circuit-switched networks were implemented first, they are an older more traditional technology. Packet-switched networks are newer more flexible networks. A wide variety of new applications are being implemented to take advantage of the flexibility of these packet-switched networks.
In a packet-switched network, packets may take a variety of different paths to arrive at a given destination. A message is first fragmented into packets, communicated across a network, and then combined back into the original message. Since the packets do not all take the same path, packet-switched networks have gained wide acceptance. For example, if a link goes down on a path, the packets can all be re-routed and still reach their destination with minimal effort.
In general, packet-switched networks are being widely deployed and will continue to be widely deployed in the foreseeable future. However, packet-switched networks are not without their problems and the advent of new technologies and applications highlight some of these problems. For example, one of the slower aspects of a packet-switched communication session is the initial setup of the call. In addition, in many applications, such as push-to-talk, etc., there are times when a full circuit is not required, but instead there is a need to transmit just a few bits. Unfortunately, conventional packet-switched technologies and protocols were not initially designed for these types of applications and, as such, perform poorly when these applications are implemented.
An example of a conventional implementation of a packet-based network will be shown in Fig. 1A and FIG. 1B. Fig. 1A displays a conventional message process flow diagram. In FIG. 1A, a Mobile Station (MS) 100 is shown. The MS 100 is in communication with a Base Station Subsystem (BSS) 102. The BSS 102 includes a Base Transceiver Station (BTS) 104 that is in communication with a Base Station Controller (BSC) 106. The BSC 106 also includes a Call Processor (CP) 108, a Resource Manager (RM) 110, and a Routing Agent (RA) 112. The RA 112 is in communication with an MSC 120 and a Packet Control Function (PCF) 114. The BSC 106 communicates with a Mobile Switching Center (MSC) 120 and a PCF 114. The PCF 114 is in communication with an IP network 116. An Authentication, Authorization, and Accounting (AAA) server 122 may be accessed through the IP network 116. A PDSN 118 is also in communication with the IP network 116.
In a conventional system, the MS 100 generates and sends an origination message 124 to the BTS 104. Origination for routing 126 is performed between the BTS 104 and the RA 112. The BTS 104 sends a base station acknowledgment message (BS Ack) 130 to the MS 100 indicating that the origination message 124 has been received. The RA 112 communicates the origination 128 to the Mobile Switching Center (MSC) 120. The MSC 120 conducts a setup conversation 132 with the RA 112. The RA 112 communicates a resource allocation request 134 to the RM 110. The RM 110 and the CP 108 allocate resources as shown by 136. The RM 110 sends a resource allocation response 138 to the RA 112. The RA 112 communicates a request for call setup 140 to the CP 108. The CP 108 communicates a response to the call setup 142. The RA 112 communicates a request to radio link setup 144 to the CP 108. The CP 108 and the BTS 104 allocate channel resources as shown by 146. The CP 108 generates a response to radio link setup 148. A channel assignment process 150 is performed between the CP 108 and the MS 100. The CP 108 communicates with the Packet Control Function (PCF) 114 to allocate PCF resources for packet data session 152. The PCF 114 communicates a response to allocate PCF resources for packet data session 154 with the CP 108.
FIG. 1B displays a continuation of the conventional message process flow diagram shown in FIG. 1A. In FIG. 1B, the CP 108 communicates with the PCF 114 to request connect PCF resources for packet data session 156. The PCF 114 communicates with the Packet Data Service Node (PDSN) 118 to setup/connect an A10 interface 158. The PCF 114 communicates with the CP 108 to connect PCF resources for packet data session 160. The RA 112 sends a Service Connect (SC) request 162 to the CP 108. The CP 108 and the MS 100 perform a service connection/negotiation process 164. The CP 108 sends a service connection response 166 to the RA 112. The RA 112 sends a Sat present message 168 to the MSC 120 and, as a result of the foregoing, data 170 may be communicated between the MS 100 and the PDSN 118.
It is clear from the foregoing process flow diagram that a number of steps must be accomplished to setup a call in a packet-based network. The various steps require time to setup the call. In addition, many of the steps are required before other steps can be accomplished. The foregoing process results in more cost for the operating network, dissatisfied customers because of the user delay, and ultimately, may even limit the types of applications that can be implemented in the network.
Thus, there is a need for reducing the time for call setup in a packet-switched network. In addition, there is a need for methods that facilitate the efficient operation of packet-switched networks.